Since February, the wire train has been installing power lines on the East Rail Line's Peña Boulevard segment. The "constant tension stringing unit" or CTSU, was manufactured by Tesmec S.p.A. of Grassobbio, Italy.

RTD FasTracks' Eagle P3 is the first U.S. transit project to employ the $1.9-million CTSU for the installation of an overhead catenary system.

The CTSU can install up to 4,600 feet of OCS wire in a day, whereas it would take up to four days to install the same length of wire through traditional methods. When outfitted to string wire, the track-mounted CTSU stretches out to 140 feet in length and weighs in at 153,000 pounds.